Positive displacement machines are widely used in modern engineering. Many of them are products of mass or large-scale production.
Therefore it is highly desirable that these machines possess:
as high as possible reliability;
as high as possible specific power and, accordingly, as low as possible specific material consumption in manufacturing;
as great as possible efficiency and, accordingly, as low as possible specific energy consumption per unit of performance, and last but not least,
as great as possible pliability to unification regardless of a specific application.
As far as such machines are based on converters of the direction of motion, the combined attainment of said requirements is substantially dependant upon the development of the latter.
Converters of the direction of motion for positive displacement machines generally comprise a shaft and an optional working element (usually rigidly) connected to the shaft capable either of affecting a fluid (liquid or gaseous) medium during the rotation of the shaft or of taking up the pressure of such medium and converting it into the rotation of the shaft.
Widely known is, for example, a vane converter of rotary motion comprising a shaft rotatably mounted on at least one bearing and at least one vane preferably radially fixed to the shaft (see, for example: (Politechnical Dictionary. Soviet Encyclopaedia Publishing House, Moscow, 1976, p. 260, entry Vane Machine)).
As specific references to the utilization of the converters of such type can be cited: Rotor Pump (U.S. Pat. No. 3,985,473); Vortex Turbo-Machine (Accepted Application of Japan 2-291499 (1990)); Positive Displacement Engine (Soviet Author's Certificate 600323) and many other pumps, compressors and hydraulic or pneumatic engines.
Vane converters and positive displacement machines based thereon are sufficiently widespread and, as a rule, are rather reliable. Some of them have rather high efficiency and specific power.
However they are so diverse in designs that only classification lists, not speaking of the detailed description of the prior art, can take tens of pages. In the practice of public production and consumption, where since long time is being observed a tendency towards increasing of a proportion of hydraulic and pneumatic devices in the total mass of industrial production, said diversity results in unjustified industrial and operational costs.
Therefore there exists an evergrowing demand for providing such reversible mechanical converter of direction of motion on which could be generally based designs of essentially different as for their application machines and, in particular, positive displacement machines.
It is expedient that designs of such converters are based on general principles of providing spatial, and more particularly, spherical mechanisms such as "universal hinge" (see, for example, M.: Hayka, 1988--The Theory of Mechanisms and high schools.--4-th revized edition. Moscow, Nauka Publishing House, 1988).
A common reversible converter of direction of motion of such type comprises a body, a shaft rotatably mounted in the body, a guide rigidly connected to the shaft, and at least one element operatively connected with the guide for taking up the rotation of the shaft or to transmit rotation to the shaft. Then, the geometric axes of rotation of all members cross each other at one point (Ibid. pp. 168-172, FIGS. 8.3 and 8.4). In particular, shown in FIG. 8.3 spherical four-member assembly comprises a body in the form of a carrier ring having projections spaced at an angle of &gt;0.degree. to &lt;90.degree., two shafts jointed in said projections each of which being either an input or an output depending on the connection to an engine and each of which being rigidly connected with guides in the shape of forks (or yokes) articulated at the ends by means of a spider.
This device serves only for transmission of rotation at an angle to a geometric axis of the input shaft and cannot be used in positive displacement machines.
It should be noted that further attention must be paid to "rotor" positive displacement machines of which an acceptable analog for a comparison with the invention can be, for example, "Rotor Pump or Engine with Spherical Body" according to U.S. Pat. No. 5,127,810.
Said positive displacement device comprises a movable body in the form of a body of revolution (and particularly in the form of the mentioned sphere) divided into two hemispherical parts by means of a blade-type working element (and particularly, disk) connected to a reversible converter of direction of motion adapted to convert rotary motion (of the body) into oscillating motion of the disk (or vice versa). Said converter is based on opposed wedge-like members mounted in the body's interior and lying at opposite sides of the disk being pivotally connected therewith, the geometric [pivotal] axes of rotation of said wedge members being orthogonal to one another and intersecting at the sphere centre.
Having rather high specific power and acceptable efficiency, said positive displacement machine reveals lower reliability when higher mechanical loads are exerted upon said wedge-like members and joints connecting said members with the disk.